Investigators Cautious About Providing Details In Boston Attack

Investigators are gathering evidence related to the blasts. Law-enforcement officials have been cautious about providing any details. NPR's counterterrorism correspondent Dina Temple-Raston is here with the latest. And Dina, do investigators have any leads?

DINA TEMPLE-RASTON, BYLINE: Well, they're actually echoing the president - being very, very cautious about providing any details in this attack. And they've warned that it could take some time before they can definitively say who was behind this. They've been already comparing this attack to the Eric Rudolph case. That was when a similar kind of explosion went off in the 1996 Olympic Games in Atlanta. And you recall, they got that investigation - in the beginning - exactly wrong. They accused a security guard named Richard Jewell of planting the bomb. And it took, literally, years to build a case against Eric Rudolph, and finally find him guilty of the crime. So officials I talked to said they wanted to step back rather than make that sort of mistake again.

SIEGEL: You mean, they're holding that up as an example of what they don't want to do right now?

TEMPLE-RASTON: Exactly, that this is the concern; that if they rush out too much with information, that it'll get momentum and it will queer the investigation.

SIEGEL: They're not telling you this is like an Eric Rudolph case here, necessarily. That's not what they mean by that.

TEMPLE-RASTON: His explosive was a very generic explosive. This seems to be, on first blush, a very generic explosive, which makes it hard to follow.

SIEGEL: OK. Let's talk about the evidence that investigators will be examining - already are examining, and will continue to do so, to try to figure out who did this. What are they looking at?

TEMPLE-RASTON: Well, as Tovia Smith said earlier...

SIEGEL: Lots of pictures.

TEMPLE-RASTON: ...lots of pictures. And we understand that they're still looking for unexploded devices near the race course. There are hundreds of possible suspicious packages that might be there, in these backpacks. So they need to go through every single one of them to make sure that there's nothing there.

And there might not be clues there. I mean, if there is, in fact, unexploded devices, there could be fingerprints left on them - or materials - that can help investigators. But again, with a moving story like this, there's a lot of misinformation. So people are trying to be very careful, and going through this as meticulously as possible. They will also be looking at security and other footage of the race, to see if they can find clues there. They're interviewing witnesses in the hospitals. This investigation, really and truly, has only just begun.

SIEGEL: And what - if anything - definitive, really, has been released about this?

TEMPLE-RASTON: Well, not much. But we know that the police and the FBI said there was no specific threat, and no specific intelligence, to indicate that the Boston Marathon might be a target. We know, according to Boston Police - and contrary to some early reports - that there is no person of interest, or suspect, in custody. We know that the police and the FBI have been dispatched to Boston hospitals, and they're interviewing people there. And we understand that the bombs were - and this is in the words of the police - powerful devices.

But of course, what we don't know is the big question - which is, who did this, and why.